Spark plug tester



July 5, 1932. KQONS 1,866,113

SPARK PLUG TESTER I Filed March 15, 1951 2 Sheets-Sheet 1 l 1 I I I I l 1' 1 2 I f I i i I l l I 1 I l I I I I 1 I I I I I a6-\+-- I l L------/- I I| 6 IKI\I;IENT JR July 5, 1932. M. B. KOONS SPARK PLUG TESTER Filed Iarch l3. 1951 2 Sheets-Sheet 2 lNVENTOR Patented July 5, 1932 UNITED STATES PATENT OFFICE means 3. xoous, or rounes'rown, 01110, assrenoa or ONE-HALF ro EDDIE sram- E 33001:, or YOUNGSTOWN, OHIO SPARK PLUG TESTER Application filed March 13, 1931. Serial No. 522,237.

My invention relates to spark plug testers and provides means whereby ignition engine spark plugs may be quickly and economically tested under operating conditions.

i I provide a spark plug tester having means associated therewith for automatically switching a spark plug under test and an electric potential supply in circuit relation with each other as soon as fluidunder pressure is supplied to the chamber in which the spark electrodes of the spark plug operate.

, More particularly, I provide a spark plug tester comprising a casing, a spark coilhoused within said casing, a socket mounted on said casing, means within said socket for receiving the sparkin end of a spark plug, means for producing iluid pressure within said socket greater than atmospheric pressure when said spark plug is placed therein, and a switch a 5 mrated bysaid fluid pressure for connecting and disconnecting said spark coil in circuit with said spark plug.

With these and other provisions in view,

the invention consists in the construction and novel combination and arrangement of parts hereinafter fully described, illustrated in the accompanying drawings and pointed out in the claims appended hereto; it being understood that various changes in the form, proportion and minor details of construction,

within the scope of the claims, maybe resorted to without departing from the spirit of the invention or sacrificing any of the advantages thereof.

In the drawings,

Figure 1 is a plan view of a spark plug tester constructed in accordance with my invention;

Figure '2 is an elevational view of the spark 4 plug tester shown in Figure 1;

Figure 3 is a view similar to Figure 2 of another modification of my invention; 7

Figure 4: is a circuit diagram of the spark plug tester, and i Figure 5 is an elevational view partly in 2 cross section of the automatic fiuid'pressure operated switch.

Referring to the drawings, 1 represents a spark plug tester constructed in accordance with my invention which comprises abox-like casing 2 having a base 3 and a cover 4. Within the casing 2 on the base 3 is mounted a spark plug coil 5 of any suitable type such, for example, as that used in model T Fords. This spark plug coil 5 is energized from a battery 6" or other suitable source of supply through binding posts 7 and 8 that are conveniently mounted on the side of the casing 2. Mounted on the cover 4 of the casing 2 is a combined stud 9 and air chamber 10. The air chamber 10 is slightly tilted so that one may look through its upper end which is provided with a transparent cover 11 held in place by a cap 12 threaded on to the end 7 of the casing 10. The lower end of the chamber 10 is provided with a threaded inner portion for the reception of a spark plug 13 which is to be tested under operating conditions. When the spark plug 13 is screwed in place in the chamber 10, an air-tight chamber is formed around its spark terminals or points. The stud 9 is hollow and is connected within the casing 2 by means of a pipe 14 to another stud 15 which is also mounted on the cover 4 of the casing2. The stud 15 is provided with a coupling 16 of T shape, which in turn supports an air gauge 17 calibrated up to at least 150 pounds per square inch air pressure. The horizontal portion of the T- pipe 16 is connected by means of a nipple 18 to another T-pipe 19. The vertical portion of the T-pipe 19 has a fluid pressure operated switch 20 connected to it by means of a bushing 21.

The switch 20 is more clearly illustrated in Figure 5 and consists of a verticalpiston 22 which operates within a vertical pipe 23. Mounted on the top of the pipe 23 is an electrode 24 which is suitably insulated from the pipe 23 and is secured in place by means of a bushing 25 threaded to the top of the pipe 23. The metal pipe 23 forms one terminal of the switch and the electrode 24 forms the other terminal. When the pressure within the pipe 19 reaches such a value that it is sufiicient to I lift the piston 22 and force it into contact with the electrode 24, then the switch is automatically closed. When the air is released from the pipe 19 the piston 22 drops to its normal position out of contact with the electrode 24, thereby opening the switch.

The other horizontal portion of the T-pipe 19 is connected by means of a nipple 26 to a valve 27. This 'valve is provided with a handle 28 for opening and closing the valve 27. The other side of the valve 27 is provided with means 29 for connecting the pipe to a suitable source of fluid, such as air under a pressure of at least 150 pounds per square inch.

As illustrated in the circuit diagram, Figure 4, the electrode 24 is connected by means of an insulated conductor 3.0 to the term nal post 7. The other electrode 22 of the switch is;grounde d to {the pipe 19 which is in turn connected by means of aninsulated conductor 31 to one terminal of the secondary c011 oithe transtormer 55. The other term-inalioat the secondary coil of the transformer 5 is connected :by means of an insulated electrical conductor '32 4136) the outer terminalof the spark plug which is to be tested. One end of the-conductor 32 is provided with a handy spring clip for ready attachment to and detachment from the outer terminal of spark .plugs to be tested. The other end of the conductor 32 isconnected to a binding ipost34 mounted on the side of the casing 2, as shown in Figure 1. The binding post 34 is in turn connected to a secondary winding 35 of the transformer 5.

A manually operated push button switch 36 is mounted in the side ot'the casing 2 for putting the device in operation regardless of the pressure operated switch 24. fine terminal of the switch 36 is connected to the binding post 7 by a conductor37 and the other terminal is grounded to the pipe 14 .by means of a conductor 38. The primary coil 39 of the transformer 5 has one of its terminals connected to the conductor 38 and the other of its terminals connected to the .contactor of the spark coil 5. The contactor-40operatesinthe usual manner to make contact with a terminal 41 when the coil 39 isdeenergized and to :break the circuit. when the .coil 39 is energized. The cont-actor 40 operates automatically to make and break the circuit as .long as either the switch- 24 or the switch 36 is closed. The terminal 41 is connected by a conductor 42 to the binding post '8. The battery 6, as pointed out above, is connected to the binding posts 7 and 18 by means of conductors 43 and 44.

In the above description I "have referred to the spark coil 5. This'term is intended to include any suitable means, such as that shown in Figure 4, for producing an intermittent potential for causing the spark plug 13 to spark in its normal manner. It will, of course, be understood that any suitable means may :be used for this purpose but I prefer to use the compact induction type spark coil.

operation is repeated for every spark The device is operated in the following manner. A spark plug 13 to be tested is screwed into place in the lower end of the chamber 9 and the spring clip 33 is snapped over its outer terminal. The conduit or connecting means 29, having been previously connected to a source of air supply, the handle 28 is turned so as to open the valve 27, thereby increasing the air pressure in the chamber 10 to any desired amount, as indicated by the pressure gauge 17. At the same time the air pressure operates the switch 20 and closes a circuit through the conductor 30., conductor .43, battery 6, conductor 44, conductor 42, terminal 41, cont-actor 40, primary coil39, conductor 38 and pipe 14.

Thisicircnit causes the battery 6 to energize the coil 39, which in turn causes the contactor 40 to operate to make and break the circuit. This causes the secondary coil 35 to be energized by an. exceedingly high voltage. The terminals of a secondary coil 35 are connected to the spark plug 13 by the conductor 32 and-to thecham'ber 1O eby-the'conductor 31. The high voltage from the secondary coil 35 is thereby impressed on the spark points 45 and 46 of the spark plug 13, causing the latter to spark every time the circuit is opened and closed bythe contactor 40 ina well known manner. The sparking points 45 and 46 of the spark plug are within the chamber 10 and are caused to operate under normal operating conditions at fluid pressure, the pressure within thecha-mber 10 being maintained at any desired magnitude.

After the spark plug 13 has been tested, the handle 28 is turned so as to close the valve 27. The :air pressure being shut off, the pressure operated .swi'tch then opens automaticall-y -a111d cuts out the operation of the ignition system.

' The spark plug is then takenout and this 1n that is tested. It will be noted that the 31113 manual operations necessary are the placing cat the spark plug in the chamber 10 and the manual movement of the handle 28. The switch for connecting the i nition system to the spark plus is operated automatically and no manual operations are necessary for con necting and disconnecting the ignition switch 36 is an auxiliary switch which may be used when desired, for example, :in case the automatically eperated switch fails to work or needs repair.

Referningto Figure 3., I illustrate a modification in which the chamber 10 and gauge 17 are mounted on a common standard 47. which in turn supports a T-pipe 48. The chamber 10 and gauge 17 are connected to the horizontal portions of the T-pipe 48 by means of nipples 49 and 50. 1 The standard 47 is mounted on the cover 4 of the casing 2 and is preferably deadened so that no air will lealk through it so as to reduce the presmg said spark coil in circuit -1,se'e,1 13

sure in the chamber 10. The modification illustrated in Figure 3 operates in the same manner as that described above in connection with the first modification.

The valve 27 is provided with an air outlet port 51 for releasing air from the pipe line to the chamber 10 as soon as the valve 27 is turned oil". This feature insures the operation of the pressure operated switch 20 when the air is turned off.

From the above description it will be ap parent that I provide a simple, compact, economical and automatic spark plug tester which is a distinct advance over similar devices of the prior art.

I claim:

1. A spark plug tester comprising in combination a casing, a spark coil housed within said casing, a socket fixedly mounted on said casing, means within said socket for receiving the sparking end of a spark plug, means for producing a fluid pressure greater than atmospheric within said socket when a spark plug is therein, a valve for controlling the fluid pressure, and a switch operated by said fluid pressure for connecting and disconnectwith said spark plug, said switch being operatively connected between the valve and the casing.

2. A spark plug tester comprising in combination a casing, a spark coil housed within said casing, a socket fixedly mounted on said casing, means within said socket for re ceiving the sparking end of a spark plug, means for producing a fluid pressure greater than atmospheric within said socket when a spark plug is therein, a switch operated by said fluid pressure for connecting and disconnecting said spark coil in circuit with said spark plug, and means for connecting and disconnecting a shuntcircuit across said switch.

3. A spark plug tester comprising in combination a fluid pressure chamber adapted to receive a spark plug to be tested, a source of high potential current, a source of fluid pressure in communication with the chamber, a fluid pressure circuit closer responsive to the pressure in said chamber through which the spark plug is connected to the current source when a predetermined pressure is reached in the chamber, and a valve for controlling the flow of fluid to the chamber.

4. A spark plug tester comprising in combination a fluid pressure chamber adapted to receive a spark plug to be tested, a source of high potential current, a source of fluid pressure in communication with the chamber, a fluid pressure circuit'closer responsive to the pressure in said chamber through which the spark plug is connected to the current source when a predetermined pressure is reached in the chamber, a valve for controlling the flow of fluid to the chamber, saidfluid pressure circuit closer being operatively connected between the chamber and the valve.

5. A spark plug tester comprising in combination a fluid pressure chamber adapted to receive a spark plug to be tested, a source of high potential current, a source of fluid pres sure in communication with the chamber, a fluid pressure circuit closer responsive to the pressure in said chamber through which the spark plug is connected to the current source when a predetermined pressure is reached in the chamber, and means for connecting and disconnecting a shunt circuit across said circuit closer.

6. A device of the character described comprising a fixedly supported pressure chamber, means for mounting a spark plug with its sparking terminals exposed to the pressure in the chamber, means for producing a fluid pressure greater than atmospheric in the chamber, means for supplying an automatically interrupted high potential current to the sparking end of a mounted spark plug, a fluid pressure circuit closer responsive to the pressure in said chamber through which the spark plug is connected to the current source when a predetermined pressure is reached in the chamber, and a valve for controlling the flow of fluid to the chamber.

7. A device of the character described com prising a fixedly supported pressure chamber, means for mounting a spark plug with its sparking terminals exposed to the pressure in" the chamber, means for producing a fluid pressure greater than atmospheric in the chamber, means for supplying an automatically interrupted high potential current to the sparking end of a mounted spark plug, a fluid pressure circuit closer responsive to the pressure in said chamber through which the spark plug is connected to the current source when a predetermined pressure is reached in the chamber, a valve for controlling the flow of fluid to the chamber, and means for connecting and disconnecting a shunt circuit across said circuit closer.

8. A device of the character described comprising a fixedly supported pressure chamber, means for mounting a spark plug with its sparking terminals exposed to the pressure in the chamber, means for producing a fluid pressure greater than atmospheric in the chamber, means for supplying an automatically interrupted high potential current to the sparking end of a mounted spark plug, a fluid pressure circuit closer responsive to the pressure in said chamber through which the spark plug is connected to the current source when a predetermined pressure is reached in the chamber, and a valve for controlling the flow of fluid to the chamber, said fluid pressure circuit closer being operatively connected between the chamber and the valve.

9. A device of the character described comprising a fixedly supported pressure chamber, means for mounting a spark plug with its sparking terminals exposed to the pressure in the chamber, means for producing a fluid pressure greater than atmospheric in the chamber, means for supplying an automatically interrupted high potential current tothe sparking end of-a mounted spark plug, a fluid pressure circuit closer responsive to the pressure in said chamber through which the spark plug is connected to the current source when a predetermined pressure is reached in the chamber, a valve ,for controlling the flow of fluid to the chamber, said fluid pressure circuit closer being operatively connected between the chamber and the valve, and means for connecting and disconnecting a shunt circuit across said circuit closer.

10. A spark plug tester comprising in combination a fluid pressure chamber fixed in position, means for mounting the spark plug in the pressure chamber, means. for producing a fluid pressure greater than atmospheric around the sparking end of a spark plug, a transparent wall in the cylinder through which the sparking terminals of the plug may be observed, means for supplying an automatically interrupted high potential currentto the sparking end of the plug, a fluid pressure circuit closer responsive to the pres sure in said chamber through which the spark plug is connected to the current when a predetermined pressure is reached in the chamber, and a valve for controlling the flow of fluid to the chamber, said fluid pressure circuit closer being operativelyconnected between the chamber and the valve.

11. A spark plug testercomprising in combination a fluid pressure chamber fixed in position, means for mounting the spark plug in the pressure chamber, means for pro ducing a fluid pressure greater than atmospheric around the sparking end of a spark plug, a transparent wall in the cylinderi through which the sparking terminals of the plug may be observed, means for supplying an automatically interrupted high potential current to the sparking end of the plug, a fluid pressure circuit closer responsive to the pressure in said chamber through which the spark plug is connected to the current when a predetermined pressure is reached in the chamber, a valve for controlling the flow of fluid to the chamber, said fluid pressure circuit closer being operatively connected between the chamber and the valve, and means for connecting and dlsconnectmg a shunt circuit across said switch.

In testimony whereof I have hereunto set my hand.

MORRIS B; KOONS.

CERTIFICATE OF CORRECTION.

Patent No. 1,866,113. July 5, 1932.

MORRIS B. KOONS.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 2, line 129, for "deadened" read deadended; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 6th day of September, A. D. 1932.

M. J. Moore,

(Seal) Acting Commissioner of Patents.

CERTIFICATE OF CORRECTION.

Patent No. 1,866,113. July 5, 1932.

MORRIS B. KOONS.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 2, line 117, after the word "switch" first occurrence, insert a period and the words The manually operated switch; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 22nd day of November, A. D. 1932.

M. J. Moore, (Seal) Acting Commissioner of Patents. 

